private void tlbtnSumDetailed_Click(object sender, EventArgs e)
        {
            DataSet ds = null;

            billinfo.Handle = tltxtHandle.Text;
            billinfo.Units  = tltxtUnits.Text;
            ds = baseinfo.BuyStockSumDetailed(billinfo, "tb_StockSumDetailed", dtpStar.Value, dtpEnd.Value);
            dgvStockList.DataSource = ds.Tables[0].DefaultView;
        }